Staining of native and grafted exocrine rat pancreas by an interleukin-2 receptor specific monoclonal antibody.

Immunohistological studies of native and grafted rat pancreas tissue with mouse anti-rat monoclonal antibodies revealed an unexpected staining pattern of MRC Ox 39 which binds specifically to rat interleukin-2 (IL-2) receptors. While the cytoplasm of acinar cells of native pancreas was stained, the lumina of the acini remained uncoloured. In grafted exocrine tissue, the staining pattern was quite reverse. Only the apical cytoplasm of acinar cells was stained while the acinar lumina exhibited an intense stain. Common binding sites shared between the IL-2 receptor and a hypothetical exportable protein in acinar cytoplasm could explain these observations.